Ideas for lifting AC unit to the top of a RV

I do not have two strong young people around to lift a replacement AC unit to the top of our RV. The roof is about 11' off the ground and the AC weighs 110lbs.

I do have a 6' high scaffolding to cut the height in half, but pretty sure two 70 year old guys (me and a buddy) could not "press" the 110 pounds 6' at a time.

I need your ideas of how to accomplish this task.